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Jolly Mountain Fire, August 2017 Kittitas

Out · last detection 17 Sept 2017, 10:25 UTC

The fire started on 11 August 2017 in Kittitas, United States, and satellites saw it burning for 38 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 15,438 hectares, spread across a single county.

It is the 29th largest in Washington since 2016 (of 285 with a page). Number 49 in United States in 2017, of 619.

Compare with…

Suggestions: Three Queens · 2026Jack Creek · 2017Labor Mountain · 2025King · 2026

Burnt area
15,438ha
official perimeter (MTBS / NIFC)
Duration
≈ 38days
11 Aug 2017 – 17 Sept 2017
Counties hit
1
counties
Started on
11 Aug
2017
Heat detections
4,040
in a single hotspot: 327 MW
Danger at start
39
Very high · FWI index
Average daily power
1.3GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 11 Aug17 Sept
17 Sept 2017

How it evolved, day by day

12 Aug 2017 · 51 MW · 23 14 Aug 2017 · 7 MW · 2 15 Aug 2017 · 1 MW · 1 16 Aug 2017 · 46 MW · 10 17 Aug 2017 · 7 MW · 6 18 Aug 2017 · 12 MW · 6 19 Aug 2017 · 31 MW · 4 20 Aug 2017 · 3 MW · 3 21 Aug 2017 · 232 MW · 12 22 Aug 2017 · 1,261 MW · 48 23 Aug 2017 · 764 MW · 64 24 Aug 2017 · 2,780 MW · 70 25 Aug 2017 · 462 MW · 85 26 Aug 2017 · 986 MW · 83 27 Aug 2017 · 125 MW · 45 28 Aug 2017 · 1,255 MW · 97 29 Aug 2017 · 1,495 MW · 117 30 Aug 2017 · 6,048 MW · 208 31 Aug 2017 · 2,122 MW · 349 1 Sept 2017 · 5,429 MW · 204 2 Sept 2017 · 5,999 MW · 291 3 Sept 2017 · 1,279 MW · 273 4 Sept 2017 · 2,631 MW · 339 5 Sept 2017 · 4,093 MW · 284 6 Sept 2017 · 1,090 MW · 205 7 Sept 2017 · 1,407 MW · 168 8 Sept 2017 · 418 MW · 97 9 Sept 2017 · 1,475 MW · 53 10 Sept 2017 · 500 MW · 122 11 Sept 2017 · 1,101 MW · 239 12 Sept 2017 · 1,897 MW · 253 13 Sept 2017 · 320 MW · 144 14 Sept 2017 · 87 MW · 12 15 Sept 2017 · 255 MW · 63 16 Sept 2017 · 120 MW · 49 17 Sept 2017 · 9 MW · 11
12 Aug 19 Aug 25 Aug 30 Aug 31 Aug 6 Sept 12 Sept

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

31°high
59km/h · peak gust
12%lowest humidity

It had gone 55 days without rain (1 mm or more) when it started. Rain came after the fire: 3.1 mm on 18 Sept.

This area had burned before

No earlier perimeters overlap this fire since 2016, when the satellite record begins.

How big is it?

10 km
It burned the equivalent of 9.7% of the area of London (154 km² against 1,583 km²).

London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).

This compares size, not location: both shapes are at the same scale, north up, centred on each other.

What happened to each county

  1. Kittitas where it started
    15,477 ha reached on 12 Aug
    2.6 %

Burnt area inside each county, from crossing the official perimeter with administrative boundaries. The distance runs from the point marking the centre of each area to the nearest fire: staying a kilometre away does not mean it reached the houses.

People and buildings inside the perimeter

GHSL 2015
Built-up area0.14 ha
Residents< 20

Inside the perimeter there were about 0.14 hectares of built-up land and almost nobody lived there (GHSL 2015, satellite-based estimate).

This is an estimate on 100 m cells, made from satellite imagery and census data: it does not mean that homes burned or that anyone was harmed. The perimeter also contains land that never burned.

Source: Global Human Settlement Layer (GHS-BUILT-S and GHS-POP R2023A), European Commission Joint Research Centre (JRC), © European Union, CC BY 4.0. Sum inside the perimeter computed by WorldFires. human-settlement.emergency.copernicus.eu

The weather day by day

ECMWF ERA5 reanalysis at the fire location, the standard reference for past weather, and the Canadian Fire Weather Index (the same system Copernicus uses), computed by WorldFires from that data. Days after the fire run until the first rain.

Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

Day High Min. humidity Peak gust Rain Danger (FWI)
11 Aug 28.4 °C 22 % 37 km/h 0.3 mm Very high 39
12 Aug 23.0 °C 41 % 44 km/h 0.1 mm High 30
13 Aug 17.7 °C 47 % 57 km/h 1.3 mm Moderate 14
14 Aug 18.9 °C 35 % 41 km/h 0.0 mm Moderate 19
15 Aug 22.2 °C 24 % 44 km/h 0.0 mm High 29
16 Aug 22.0 °C 40 % 55 km/h 0.0 mm High 30
17 Aug 22.0 °C 32 % 43 km/h 0.0 mm High 28
18 Aug 20.4 °C 42 % 58 km/h 0.0 mm High 29
19 Aug 20.0 °C 31 % 50 km/h 0.0 mm High 28
20 Aug 20.7 °C 36 % 46 km/h 0.0 mm High 27
21 Aug 26.2 °C 25 % 34 km/h 0.0 mm High 29
22 Aug 28.1 °C 19 % 41 km/h 0.0 mm High 37
23 Aug 23.0 °C 32 % 44 km/h 0.0 mm High 33
24 Aug 16.5 °C 37 % 59 km/h 0.0 mm High 32
25 Aug 21.9 °C 18 % 37 km/h 0.0 mm High 32
26 Aug 27.3 °C 15 % 23 km/h 0.0 mm High 33
27 Aug 29.7 °C 16 % 28 km/h 0.0 mm High 36
28 Aug 30.7 °C 15 % 27 km/h 0.0 mm High 37
29 Aug 31.4 °C 14 % 31 km/h 0.0 mm Very high 40
30 Aug 21.4 °C 32 % 49 km/h 0.0 mm High 38
31 Aug 21.3 °C 33 % 48 km/h 0.0 mm High 33
1 Sept 29.0 °C 13 % 38 km/h 0.0 mm Very high 40
2 Sept 30.7 °C 12 % 43 km/h 0.0 mm Very high 46
3 Sept 30.7 °C 12 % 44 km/h 0.0 mm Very high 46
4 Sept 28.6 °C 20 % 40 km/h 0.0 mm Very high 43
5 Sept 25.2 °C 26 % 41 km/h 0.0 mm High 38
6 Sept 26.9 °C 24 % 31 km/h 0.0 mm High 34
7 Sept 24.6 °C 42 % 36 km/h 0.4 mm High 28
8 Sept 20.6 °C 55 % 37 km/h 0.0 mm High 22
9 Sept 17.4 °C 45 % 44 km/h 0.0 mm High 24
10 Sept 20.4 °C 29 % 36 km/h 0.0 mm High 25
11 Sept 27.7 °C 15 % 35 km/h 0.0 mm High 35
12 Sept 23.1 °C 38 % 53 km/h 0.0 mm High 33
13 Sept 16.1 °C 32 % 41 km/h 0.0 mm High 29
14 Sept 18.1 °C 22 % 30 km/h 0.0 mm High 27
15 Sept 18.5 °C 20 % 24 km/h 0.0 mm High 28
16 Sept 14.6 °C 31 % 38 km/h 0.0 mm High 28
17 Sept 15.5 °C 31 % 39 km/h 4.0 mm Very low 5
18 Sept after 9.5 °C 62 % 44 km/h 3.1 mm Very low 1

Before and after, from space

Drag the line to compare the same ground before the fire and after it.

Before · 4 Aug 2017
After · 24 Sept 2017

If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.

Detections table · 4,040Every satellite heat detection, one by one, with time, satellite, power and coordinates.
⬇ Download CSV Times in UTC. Each detection is a 375 m pixel: a large fire yields hundreds per pass.
Date and timeSatelliteFRP (MW)LatLon

Other fires nearby

All fires in United States ›

Frequently asked questions

How long did the Jolly Mountain Fire last?
The official perimeter only gives the start date (11 August 2017). The end comes from the heat detections inside the perimeter: it burned until 17 September 2017 (38 days from 11 August 2017), the last day with detections before more than 10 days in a row without any, so it is approximate.
How much area did it burn?
The official perimeter published by United States agencies (MTBS / NIFC) is 15,438 hectares (154.4 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Kittitas (15,477 ha, 2.6 %).
What was the weather like?
During the fire the temperature reached 31.4 °C, humidity dropped to 12 % and gusts hit 59 km/h. The fire danger index (FWI) reached 46, class Very high.
Where does this data come from?
From the official burnt perimeter of United States agencies (MTBS / NIFC, public domain), NASA FIRMS VIIRS hotspots and the administrative boundaries of United States. It is not an official report.

Where to verify it

A satellite detection is not an official report. Final figures and the fire’s status are published by each country’s emergency service.

Emergency number: 911 · Emergency number and official warnings ›

Satellite cross-check

History of this page Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

No changes since 24 October 2026.

RSS Changes to this page

Does something look wrong on this page?

This page is built from satellite data and official records, and it sometimes gets things wrong: the wrong dates, the wrong town, two fires merged into one, or something that was not a wildfire at all. If you know this fire first-hand (you live nearby, saw it, fought it or reported on it), tell us what really happened and we will check it.

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We will only use your email to reply about this report. Privacy. This is not an emergency service: if there is a fire now, call 911.

How we know this
  • Perimeter: MTBS (US Geological Survey and US Forest Service), official.
  • The official perimeter has no end date: the end is the last day with VIIRS detections inside the perimeter before a gap of more than 10 days (150 days at most), so it is approximate. 4,040 Suomi-NPP VIIRS detections on those dates.
  • We have not matched this page with any official record.
  • Weather: Copernicus ERA5 reanalysis at the fire location, in cells of about 25 km.
  • Built-up area and population come from the JRC Global Human Settlement Layer (epoch 2015, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.

How we build fire pages: methodology ›

Where this data comes from

The perimeter is official and in the public domain. For past years it comes from MTBS (Monitoring Trends in Burn Severity), run by the U.S. Geological Survey and the USDA Forest Service, which map it on Landsat and Sentinel-2 imagery. For the current and last year it comes from WFIGS at the National Interagency Fire Center (NIFC): incident perimeters mapped by fire crews, aircraft and imagery. Heat detections come from the VIIRS sensors aboard Suomi-NPP and NOAA-20, distributed by NASA FIRMS at 375 m resolution. County boundaries come from geoBoundaries ADM2 (Public Domain). The area per county is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ slightly from official figures.